Grist, Voracious Larva // Grist, the Plague Swarm

Deathtouch
Whenever Grist, Voracious Larva or another creature enters the battlefield under your control, if it entered from your graveyard or you cast it from your graveyard, you may pay {G}. If you do, exile Grist, then return it to the battlefield transformed under its owner's control. +1: Create a 1/1 black and green Insect creature token, then mill two cards. Put a deathtouch counter on the token if a black card was milled this way.
−2: Destroy target artifact or enchantment.
−6: For each